1-amino-1-halo-2, 2-dicyanoethylenes and preparation of same



United States PatentfC l-AMINO-l-HALO-Zfl-DICYANOETHYLENES ANDPREPARATION OF SAll/IE No Drawing. Application May 31, 1955,

Serial No. 512,273

6 Claims. (Cl. 260-4655) This invention is concerned with newnitrogen-containing compounds and a process for their preparation, and

relates more particularly to dicyanoethylene derivatives.Cyanohydrocarbons having a plurality of cyano groups are highly reactiveand are of interest as intermediates in the preparation of valuablederivatives. It is known to produce compounds having a plurality ofcyano groups by reactions which involve the dimerization ortrimerization of metal salts of nitriles and treatment with a halogenhalide. Thus an article by Richard Meier, Ber. 86, 1491 (1953), teachesthat ethanetetracarbonitrile is formed from sodiomalononitrile when asolution of the nitrile in absolute alcohol is treated with nitrousoxide and neutralized with acid. U. S. Patent No. 2,719,861, issuedOctober 4, 1955, discloses the formation of 2-amino-1,3,3-tricyano-2-propene from an alkali metal derivative ofmalononitrile. Cyclic trimers of acetonitrile, propionitrile, andmalononitrile have been formed by treatment of the nitriles with sodiumalcoholates and other basic materials (Schenk and Finken, Ann. 462, 273(1928), and Schwarze, I. Prakt. Chem. (2), 42, l (1890)). Otherreactions of this type are disclosed in Migrdichian, The Chemistry ofOrganic Cyanogen Compounds, pages 351-358 (Reinhold Publishing Corp.,New York, 1947).

Cyanoform and the metal salts thereof already contain sufiicientactivating cyano groups to provide a highly reactive positive group, i.e., the replaceable hydrogen or metal atom. A process which wouldintroduce a readily replaceable negative group, such as a halogen,without polymerization occurring, should provide a highly useful, lowmolecular weight intermediate for further syntheses.

It is an object of this invention to provide a new low molecular weightcompound containing a plurality of activating cyano groups and an activehalogen. Another object is to provide a process for preparing such acompound from a metal salt of cyanoform. Other objects will becomeapparent from the specification and claims.

These objects are accomplished by reacting two moles:

of hydrogen halide with one mol of an alkali metal. salt of cyanoform toproduce a 1-amino-1-halo-2,2-dicyanoethylene. In this reaction hydrogenhalide gas:

can be reacted directly with the alkali metal salt of cyanoform, butbetter results are obtained by bringing;

the reactants together in solution. The reaction mechanism by which thisunexpected product is obtained has: not been determined, but theover-all reaction is illus-- trated by the following equation in which Mrepresents: the alkali metal:

MC (ON): 2HX (NC)2C=C MX When HX represents hydrogen fluoride theproduct. is-

I 2 1-bromo 2,2-dicyanoethylene and with hydrogen iodide the product isl-amino-l-iodo-2,2-dicyanoethylene.

The, reaction is preferably carried out by passing dry hydrogen halideinto an anhydrous solution of an alkali metal salt of cyanoform,particularly in acetone solution, until the reaction is complete. Thealkali halide formed precipitates from acetone solution and is removedby filtration. The l-amino-l-halo-2,2-dicyanoethylene may be recoveredfrom the filtrate in various ways; for example, it can be precipitatedby treatment of the filtrate with a non-solvent for the dicyanoethylenederivative, such as n-heptane. The reaction is conveniently carried outat temperatures ranging from C. to 0 C. or below, but preferably in thelower temperature range. -'The pressure is not critical.

Instead of passing hydrogen halide into a solution of the alkali salt ofcyanoform, a solution of hydrogen halide can be used, c. g., by passingan aqueous solution of the cyanoform salt and an alkali halide throughan acid ion exchange resin to generate hydrogen halide in the reactionmixture. This is illustrated in Example HI.

The potassium salt of cyanoform used in the examples of this inventioncan be prepared by the reaction of potassium cyanide withbromomalononitrile:

H KCN Br-(i-(ON KC(CN); HBr as described by Cox and Fontaine in Bulletinde la lSocit Chemique de France, July-August, 948-949 (1954). Thesodium, lithium, rubidium and cesium :salts, which can be prepared in asimilar way, can also be used in the practice of this invention.

The invention is illustrated by the following examples :in which partsare'by weight.

Example 1 NH: KC(ON)3 +2HBr KBr (NC)zC=C .Dry hydrogen bromide waspassed into a solution of i 6.4 parts of the potassium salt of cyanoformin 200 parts of acetone for ten minutes. The precipitate of potassiumbromide (5.5 parts) was separated by filtration, and the filtrate wasallowed to stand overnight. filtrate was then poured into 1095 parts ofn-heptane, :and 1 part of l-amino-1-bromo-2,Z-dicyanoethylene wasobtained as a white solid. The identity of the solid was determined byits infrared spectra, using data obtained iron: the compound preparedaccording to the process described in Example IH.

l-amino-1-bromo-2,Z-dicyanoethylene is a white solid which sublimesabove C. but does not melt below 300 C. It is soluble in water andacetone and insoluble in diethyl ether and heptane. A water solutionacts as a strong dibasic acid having a PKA of 1.9.

Example 11 KO(CN): 21101 K01 (No),0=o

Dry hydrogen chloride was passed into a solution of 6.4 parts of thepotassium salt of cyanoform in 200 parts of acetone for ten minutes.After standing for one-half hour at 0 C., 3.5 parts of potassiumchloride precipitate was separated by filtration, and the filtrate wassaturated with hydrogen chloride. The reaction mixture was allowed tostand at Dry Ice temperature overnight and was then poured into 1460parts of n-heptane. The oil which separated was extracted with 360 partsdiethyl ether. On evaporation, the diethyl ether extract yielded 4 parts(63.4% yield) of l-amino-l-chloro-ZQ-dicyanoethyleneas. a light yellowsolid. The identity of the -product-wasdeterminedby"its infrared spectraand-anal material, like the -bromo" "COEIJQQIQDQ; sublimes above-100 C.,but'does-notmelt -be1ow-;300 C. In 'watensolutionjtalso ;acts asa-strong'acidfpKA 1.9). When thiscompound is irradiated with ultravioletlight at 3650A, itemits a pinkluminescence, and, when irradiatedwith'X-rays,- it einits a white luminescence. 'The latter property'makesthis compound useful as aphosphor "for fluoroscopic screens.

:EEatamp le ,111 V A solution of 56.5 parts ofa so'diuni-sawof cyanoformcontaining 14% sodium bromide in 500 parts of distilled v water wasslowly passed through a column packed with one-mole of a sulfonicacididnqexchange resin. Water "was removedfrom the strongly acidic-e'fliuent by vacuum distillation at roorn ternperature. "The resultingbrown solid (49 parts) was-heatedfin a-sublimationtube'at 100-- 120C.and- -mrn.-- pressure. Fiyepartsmf l-amino-L' bromo Z;Z-dicyanoethylenewas-obtained as a lightyellow sublimate.

Qtionareefiective catalysts for the prosslink ingflof epox-ide polymers,as demonstrated; by, the following: l-arnino-lbromo-2,2-dicyanoethylene(1%) was suspended in a solution *of an epoxidized polymer; Afilm of themixture was thenbaked for .thirty minutes .at 170"C; to

yield'a'filrn of crosslinked polyn er. V V

The compounds are also efiective insecticidal and fungicidalcompositions. .At 2% concentration in ace- "t'QHGSQIHtiOHy'1--amino1--bromo--2',2-dicyanoethy1ene-gave the following percent killsPercent German rnaches 100 Bean aphids 90 Two-spotted mites 98 nouse 45Southern army-worm 30 Since manydifierent-embodiments' of the inyentionmay be-made-without departing from the spirit and scope thereof, it isto be understood that the invention is not limited l y-the; specificillustr ations except; .tothe extent defined in the followingclaims.

' What is claimed is:

1. A compound of the class consisting ofl-amino-lhalo-2,Z-dicyandethylenes.

2-. The 9399- 1 44 1hami o: mm ma cyan e hy ene.

compound. lram owchlprqiz-dicya oe hy ene.

The grocess forproduc ing a-J-amino-l-halo-Zlfliswlq th lw whi h ompriser a t n wo oles.- eofi a 1, 554v g snrlr t d w th 0m: m of an lkali zmea xsa .of We QI Qr-m r 5-. T m qcfi s whic omp i e p ss ng s yy ro .ha ei t?i 2 1 11r0.usv sol t on. of n alk lime al .sal o gxanqf r'm.mil-the-r etion s c mp e and recover- -.ami :hakfiJflicaame hyleneformed.

6. v 'IIhenocess'whiohcomprises treatingan; alkali'metal salt. of;eyamfqnm w h s o aque ln ien. oina hydrogen halide to, form. lramino-l-halo-gkdicyauoeth Xlne..-

Re ere c s-c t mit ime r this patent UNITED: STATES. PATENTS 2.375335'Bexgelet'al; May 8, 194-5

1. A COMPOUND OF THE CLAS CONSISTING OF1-AMINO-1HALO-2,2-DICYANOETHYLENES.